Am Jagadeesh

Efficacy of perioperative pregabalin in acute and chronic post-operative pain after off-pump coronary artery bypass surgery: A randomized, double-blind placebo controlled trial

AIMS AND OBJECTIVES We evaluated the efficacy of perioperative pregabalin on acute and chronic post-operative pain after off-pump coronary artery bypass (OPCAB) surgery. MATERIALS AND METHODS Forty patients undergoing elective OPCAB surgery were randomized to pregabalin and control groups. Pregabalin group received 150 mg pregabalin 2 h prior to induction of anesthesia and 75 mg twice daily for 2 post-operative days whereas the control group received placebo at similar timings; pregabalin and placebo were administered by an anesthesiologist blinded to the drugs. Pain scores (visual analogue scale [VAS]) and sedation scores were observed at 0, 4, 6, 12, 24, 36 and 48 h after extubation. Time to extubation, tramadol consumption and side-effects were noted. VAS score was analyzed by Mann-Whitney U test. The analysis of variance test for repeated measures was used for comparison of the means of continuous variables. Group comparisons were made using the Chi-square-test. RESULTS Pain-scores at 6, 12, 24 and 36 h from extubation at rest and at deep breath were less in pregabalin treated patients ( P < 0.05). Tramadol consumption was reduced by 60% in pregabalin group ( P < 0.001). Extent of sedation, extubation times and incidence of nausea were comparable. The effect on chronic post-operative pain was not significant. CONCLUSIONS Perioperative pregabalin reduced pain scores at rest and deep breath and reduced consumption of tramadol in the post-operative period without delaying extubation and causing excessive sedation.

A comparison of a continuous noninvasive arterial pressure (CNAP™) monitor with an invasive arterial blood pressure monitor in the cardiac surgical ICU.

Accurate measurement and display of arterial blood pressure is essential for rational management of adult cardiac surgical patients. Because of the lower risk of complications, noninvasive monitoring methods gain importance. A newly developed continuous noninvasive arterial blood pressure (CNAP™) monitor is available and has been validated perioperatively. In a prospective study we compared the CNAP™ monitoring device with invasive arterial blood pressure (IAP) measurement in 30 patients in a cardiac surgical Intensive Care Unit (ICU). Patients were either mechanically ventilated or spontaneously breathing, with or without inotropes. CNAP™ was applied on two fingers of the hand contralateral to the IAP monitoring catheter. Systolic, diastolic and mean pressure data were recorded every minute for 2 h simultaneously for both IAP and CNAP™. Statistical analysis included construction of mountain plot and Bland Altman plots for assessing limits of agreement and bias (accuracy) calculation. Three thousand and six hundred pairs of data were analyzed. The CNAP™ systolic arterial pressure bias was 10.415 mmHg and the CNAP™ diastolic arterial pressure bias was -5.3386 mmHg; the mean arterial pressure (MAP) of CNAP™ was close to the MAP of IAP, with a bias of 0.03944 mmHg. The Bland Altman plot showed a uniform distribution and a good agreement of all arterial blood pressure values between CNAP™ and IAP. Percentage within limits of agreement was 94.5%, 95.1% and 99.4% for systolic, diastolic and MAP. Calculated limits of agreement were -4.60 to 25.43, -13.38 to 2.70 and -5.95 to 6.03 mmHg for systolic, diastolic and mean BP, respectively. The mountain plot showed similar results as the Bland Altman plots. We conclude CNAP™ is a reliable, noninvasive, continuous blood pressure monitor that provides real-time estimates of arterial pressure comparable to those generated by an invasive arterial catheter system. CNAP™ can be used as an alternative to IAP.

Impact of monitoring cerebral oxygen saturation on the outcome of patients undergoing open heart surgery

AIMS AND OBJECTIVES We studied the usefulness of regional cerebral oxygen saturation (rSO 2 ) monitoring during cardiopulmonary bypass (CPB) and evaluated effects of cerebral oxygen desaturation on the postoperative neurological outcome. MATERIALS AND METHODS 100 patients were randomly allocated to either control or intervention group. In the control group rSO 2 was recorded continuously, but the attending anesthesiologist was blinded. In the intervention group specific interventions were initiated in case of cerebral desaturation. Neurocognitive testing was done using a simplified antisaccadic eye movement test (ASEM) and mini-mental state examination (MMSE). Data was analyzed using Chi-square test, and unpaired t-test. RESULTS In both the groups rSO 2 declined during CPB. The decrease in rSO 2 was significant ( P < 0.001) in the control group compared to the intervention group. In the intervention group the rSO 2 mainly responded to an increase in mean arterial pressure. The area under the curve below threshold rSO 2 was significantly more ( P < 0.0001) in the control group compared to intervention group and a significant decrease in the MMSE and ASEM scores occurred in control group at one week and three months postoperatively. CONCLUSIONS Monitoring of rSO 2 during CPB can significantly decrease the incidence of postoperative neurocognitive decline.

Evaluation of continuous non-invasive arterial pressure monitoring during induction of general anaesthesia in patients undergoing cardiac surgery

Background and Aims: Continuous arterial pressure monitoring is essential in cardiac surgical patients during induction of general anaesthesia (GA). Continuous non-invasive arterial pressure (CNAP) monitoring is fast gaining importance due to complications associated with the invasive arterial monitoring. Recently, a new continuous non-invasive arterial pressure device (CNAP™) has been validated perioperatively in non-cardiac surgeries. The aim of our study is to compare and assess the performance of CNAP during GA with invasive arterial pressure (IAP) in patients undergoing cardiac surgeries. Methods: Sixty patients undergoing cardiac surgery were included. Systolic, diastolic, and mean arterial pressure (MAP) data were recorded every minute for 20 min simultaneously for both IAP and CNAP™. Statistical analysis was performed using mountain plot and Bland Altman plots for assessing limits of agreement and bias (accuracy) calculation. Totally 1200 pairs of data were analysed. Results: The CNAP™ systolic, diastolic and MAP bias was 5.98 mm Hg, −3.72 mm Hg, and − 0.02 mm Hg respectively. Percentage within limits of agreement was 96.0%, 95.2% and 95.7% for systolic, diastolic and MAP. The mountain plot showed similar results as the Bland Altman plots. Conclusion: We conclude CNAP™ provides real-time estimates of arterial pressure comparable to IAP during induction of GA for cardiac surgery. We recommend CNAP can be used as an alternative to IAP in situations such as cardiac patients coming for non-cardiac surgeries, cardiac catheterization procedures, positive Allen′s test, inability to cannulate radial artery and vascular diseases, where continuous blood pressure monitoring is required.

Transesophageal echocardiography in surgical management of pseudoaneurysm of mitral-aortic intervalvular fibrosa with aneurysms of right sinus of Valsalva and left main coronary artery

Pseudoaneurysm of mitral-aortic intervalvular fibrosa (MAIVF) is a rare complication associated with aortic and/or mitral valve surgery complicated by infective endocarditis. We report pseudoaneurysm of MAIVF in a young adult without overt cardiac disease or previous cardiac surgery. The patient had a rare combination of pseudoaneurysm of MAIVF impinging on anterior mitral leaflet causing moderate mitral regurgitation, right sinus of Valsalva aneurysm extending into interventricular septum, and left main coronary artery aneurysm. Transesophageal echocardiography helped in confirming the lesions, delineating the anatomy of all the lesions, and assessing the adequacy of surgical repair.

Predicting mortality after congenital heart surgeries: Evaluation of the Aristotle and Risk Adjustement in Congenital Heart surgery-1 risk prediction scoring systems: A retrospective single center analysis of 1150 patients

AIMS AND OBJECTIVES To validate Aristotle basic complexity and Aristotle comprehensive complexity (ABC and ACC) and risk adjustment in congenital heart surgery-1 (RACHS-1) prediction models for in hospital mortality after surgery for congenital heart disease in a single surgical unit. MATERIALS AND METHODS Patients younger than 18 years, who had undergone surgery for congenital heart diseases from July 2007 to July 2013 were enrolled. Scoring for ABC and ACC scoring and assigning to RACHS-1 categories were done retrospectively from retrieved case files. Discriminative power of scoring systems was assessed with area under curve (AUC) of receiver operating curves (ROC). Calibration (test for goodness of fit of the model) was measured with Hosmer-Lemeshow modification of χ2 test. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were applied to assess reclassification. RESULTS A total of 1150 cases were assessed with an all-cause in-hospital mortality rate of 7.91%. When modeled for multivariate regression analysis, the ABC (χ2 = 8.24, P = 0.08), ACC (χ2 = 4.17 , P = 0.57) and RACHS-1 (χ2 = 2.13 , P = 0.14) scores showed good overall performance. The AUC was 0.677 with 95% confidence interval (CI) of 0.61-0.73 for ABC score, 0.704 (95% CI: 0.64-0.76) for ACC score and for RACHS-1 it was 0.607 (95%CI: 0.55-0.66). ACC had an improved predictability in comparison to RACHS-1 and ABC on analysis with NRI and IDI. CONCLUSIONS ACC predicted mortality better than ABC and RCAHS-1 models. A national database will help in developing predictive models unique to our populations, till then, ACC scoring model can be used to analyze individual performances and compare with other institutes.

Propensity-matched analysis of association between preoperative anemia and in-hospital mortality in cardiac surgical patients undergoing valvular heart surgeries

Introduction: Anaemia is associated with increased post-operative morbidity and mortality. We retrospectively assess the relationship between preoperative anaemia and in-hospital mortality in valvular cardiac surgical population. Materials and Methods: Data from consecutive adult patients who underwent valvular repair/replacement at our institute from January 2010 to April 2014 were collected from hospital records. Anaemia was defined according to WHO criteria (hemoglobin <13g/dl for males and <12g/dl for females). 1:1 matching was done for anemic and non-anemic patients based on propensity for potentially confounding variables. Logistic regression was used to evaluate the relationship between anaemia and in-hospital mortality. MatchIt package for R software was used for propensity matching and SPSS 16.0.0 was used for statistical analysis. Results: 2449 patients undergoing valvular surgery with or without coronary artery grafting were included. Anaemia was present in 37.1% (33.91% among males & 40.88% among females). Unadjusted OR for mortality was 1.6 in anemic group (95% Confidence Interval [95% CI] – 1.041-2.570; p=0.033). 1:1 matching was done on the basis of propensity score for anaemia (866 pairs). Balancing was confirmed using standardized differences. Anaemia had an OR of 1.8 for mortality (95% CI- 1.042 to 3.094, P=0.035). Hematocrit of < 20 on bypass was associated with higher mortality. Conclusion: Preoperative anaemia is an independent risk factor associated with in-hospital mortality in patients undergoing valvular heart surgery.

Pediatric cardiac catheterization procedure with dexmedetomidine sedation: Radiographic airway patency assessment

Aims: The aim of the study was to measure airway patency objectively during dexmedetomidine sedation under radiographic guidance in spontaneously breathing pediatric patients scheduled for cardiac catheterization procedures. Subjects and Methods: Thirty-five patients in the age group 5–10 years scheduled for cardiac catheterization procedures were enrolled. All study patients were given loading dose of dexmedetomidine at 1 μg/kg/min for 10 min and then maintenance dose of 1.5 μg/kg/h. Radiographic airway patency was assessed at the start of infusion (0 min) and after 30 min. Antero-posterior (AP) diameters were measured manually at the nasopharyngeal and retroglossal levels. Dynamic change in airway between inspiration and expiration was considered a measure of airway collapsibility. Patients were monitored for hemodynamics, recovery time and complications. Statistical Analysis: Student paired t-test was used for data analysis. P < 0.05 was considered significant. Results: Minimum and maximum AP diameters were compared at 0 and 30 min. Nasopharyngeal level showed significant reduction in the minimum (6.27 ± 1.09 vs. 4.26 ± 1.03, P < 0.0001) and maximum (6.51 ± 1.14 vs. 5.99 ± 1.03, P < 0.0001) diameters. Similarly retroglossal level showed significant reduction in the minimum (6.98 ± 1.09 vs. 5.27 ± 1.15, P < 0.0001) and maximum (7.49 ± 1.22 vs. 6.92 ± 1.12, P < 0.0003) diameters. The degree of collapsibility was greater at 30 min than baseline (P < 0.0001). There was a significant decrease in heart rate (P < 0.0001), and the average recovery time was 39.86 ± 12.22 min. Conclusion: Even though airway patency was maintained in all children sedated with dexmedetomidine, there were significant reductions in the upper airway dimensions measured, so all precautions to manage the airway failure should be taken.

Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft

Aims and Objectives: Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE). Materials and Methods: Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting. Results: Hemodynamic and echocardiographic variables were compared by means of Students t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting. Conclusion: Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization.

Patient prosthesis mismatch after aortic valve replacement: An Indian perspective

Context: Perioperative period. Aims: Occurrence of PPM after AVR, factors associated with PPM, impact on mortality. Settings and Design: Teritary Care Referral Cardiac Centre. Materials and Methods: A retrospective analysis of AVR procedures at a single centre over 4 years was conducted. Demographic, echocardiographic and outcome data were collected from institute database. Rahimtoola criteria of indexed effective orifice area (iEOA) were used to stratify patients into PPM categories. Patients with and without PPM were compared for associated factors. Statistical Analysis Used: Independent t-test, chi-square test, logistic regression analysis, ROC-AUC, Youden index. Results: 606 patients with complete data were analysed for PPM. The incidence of mild, moderate and severe PPM was 6.1% (37), 2.5% (15) and 0.5% (3) respectively. There was no impact of PPM on all-cause in-hospital mortality. PPM was observed more with Aortic Stenosis (AS) compared to Aortic Regurgitation (AR) as etiology. Aortic annulus indexed to BSA (iAA) had a very good predictive ability for PPM at <16mm/m 2 BSA. Conclusions: PPM has lower incidence after AVR in this Indian population and does not increase early mortality. Patients with AS and iAA<16mm/m2BSA should be cautiously dealt with to prevent PPM.